Ok so I have one delta tail male, Spud, in a 2.5 gallon heated and filtered tank. I cleaned it 100% like I do every week but after cleaning it all and putting Spud back in, the next day I see Spud's tail have a slight slit in his tail. I didn't think it was that bad until yesterday when I see his fins a little bit clamp-ish looking. The tip of his fins have a tinge of red, and the slit is more like a gap now...

His appetite is normal, still greedy, but I love his fins and I don't want them to be history. Oh yea and he has been hanging around his cave a lot, but I don't know if that is significant or not.

Not that little blur is his little fins I think they are called pectoral fins.. They move kinda fast and the angle and color of those little fins make it look like his stomach Either way he gets Top fin betta pellets twice daily and a fasting day once a week.